If you’ve ever wanted to live in a cave, this beautiful modern home in Festus, Missouri is the perfect blend of energy efficiency and rustic living. The 17,000-square foot underground home is built right inside a sandstone cave, featuring a modern interior space that perfectly accents the unfinished sandstone walls.

Owners Curt and Deborah Sleeper used geothermal heating and smart passive design to keep it comfortable inside without the use of air conditioning or a furnace, and have said it costs the same to heat this home as it did to heat their previous 800-square foot home.

The sandstone walls act as a natural insulation, keeping it comfortable year round. There are three different chambers throughout the home, and interior roofs and coverings are placed throughout to capture remnants from the naturally shedding walls. The property includes three freshwater springs and 14 waterfalls.

This cave has previously been used as a rollerskating rink, and even a concert venue, hosting several well-known stars such as Tina Turner, Bob Seger, and Ted Nugent. The stage is located in the back chamber of the home.